This disclosure relates to power tools and particularly to devices for dispersing dust and debris from the working path of the tool.
Power tools such as circular saws, table saws, miter saws, or the like produce dust and debris as the workpiece material is cut, and in many cases the tools are used in an inherently dusty environment, such as at a construction site or in a fabrication facility. It is a common practice to mark a cut line on the workpiece as a guide for the path of the power tool. Most tools have some form of alignment feature that allows the operator to align the cutting element of the power tool with the cut line. For example, a circular saw, such as the saw 10 shown in FIGS. 1 and 2, may include a shoe plate 11 with an opening 14 through which the working tool, or saw blade, extends, and an alignment window 15 in the body of the plate. The alignment window 15 may incorporate alignment prongs 16 to allow the operator to see the line of action of the working tool, or cut line, through the window. The shoe plate may also include a notch 18 defined at the leading edge of the plate that can also be used to indicate the cut line and ensure proper alignment of the power tool cutting element, such as the blade assembly 12.
During a cut operation dust and debris frequently settles on the workpiece forward of the cutting blade, and more particularly on the leading end of the shoe plate 11. The dust can thus obscure either or both of the alignment components 15 and 18, making it hard to see the cut line as well as the alignment components. The dust can thus compromise the operator's ability to accurately follow the cut line, or at a minimum can require the operator to stop and blow the debris away from the cutting path.
Some power tools are provided with a separate blower directed at the cutting path to remove the dust and debris, but such separate blowers are often bulky. Other power tools utilize air flow from a cooling fan driven by the power tool motor. For instance, in the tool 10 shown in FIGS. 1-2, a motor housing 20 contains a motor M (FIGS. 3, 5) coupled to the blade assembly 12. The housing 20 substantially encloses the motor while defining a cavity 21 (FIG. 5) around the motor M for cooling air flow. The motor drives a fan in a fan housing 22 that draws ambient air into the motor housing 20 through inlet openings, such as openings 24 in the side of the fan housing and/or openings 25 in the lateral face of the housing. The fan is operable to draw the ambient air through the cavity and over the motor to cool the motor. Certain power tools provide an outlet opening in the motor housing that is directed toward the leading end of the shoe plate. The outlet opening in these power tools is generally aimed toward either the interface between the cutting element and the workpiece or toward the alignment features of the shoe plate. Other tools direct the airflow passing over the motor to the shroud 13 of the blade assembly 12 to roughly follow the rotational path of the cutting blade toward the workpiece.
While some prior power tools offer some form of debris blower that is integrated into the existing tool, they all suffer from the same limitations, such as limited air flow specifically directed to the alignment features or an air flow path that is too narrow to provide clearance to the cutting path and alignment features. Consequently, there is a need for a blower that can be integrated into the power tool and that is configured to provide clearance to the cutting path so that the operator can clearly visualize the cut line and the alignment features of the tool.